NEW YORK (Reuters Health) - New research suggests that fluoxetine (Prozac) plus cognitive behavioral therapy is effective for teens with depression and substance use disorder. However, the findings also suggest that much of the benefit can be achieved with cognitive behavioral therapy alone.

The authors conclude that it might be appropriate to start with cognitive behavioral therapy and then add fluoxetine in the patients who do not respond.

The findings, which appear in the Archives of Pediatrics and Adolescent Medicine, are based on study of 126 teens with a current depressive disorder, lifetime conduct disorder, and at least one non-tobacco substance use disorder, who were randomly assigned to cognitive behavioral therapy in combination with fluoxetine or placebo. The cognitive behavioral therapy was focused on the substance use disorder, not on the depression.

Dr. Paula D. Riggs and colleagues, from the University of Colorado in Denver, found that fluoxetine plus cognitive behavioral therapy provided a greater improvement according to the Childhood Depression Rating Scale-Revised than did placebo plus cognitive behavioral therapy. By contrast, no difference was noted on the Clinical Global Impression Improvement scale.

Both groups experienced a similar drop in self-reported substance use and conduct disorder symptoms as the 16-week study progressed. However, subjects in the placebo plus cognitive behavioral therapy group were more likely than those in the fluoxetine-cognitive behavioral therapy group to have a substance-free weekly urine test.

Still, the authors emphasize that while this latter finding was statistically significant, larger studies will be needed to determine if it is clinically relevant.

For patients who did not response to cognitive behavioral therapy, the authors advise that "fluoxetine should be considered, even if adolescents are not yet abstinent, with weekly monitoring of treatment adherence, substance use, adverse effects, and target symptom response."